Development of the wall labyrinth in pavement epithelium hairs of some Utricularia species

Sodium hypochlorite-digested material and scanning electron microscopy was used to study the morphology of wall ingrowths in pavement epithelium hairs of Utricularia species from the primitive section Pleiochasia (U. volubilis) and the advanced section Utricularia (U. stygia, U. intermedia). Wall ingrowths were reticulate-type in all examined species. Wall ingrowth development started with the formation of small papillae, which later lengthened and eventually fused and branched, forming a network. The sequence of wall deposition in plant hairs is given for the first time with SEM. The wall labyrinth in transfer cells of pavement epithelium hairs was found to be far from static. Different stages of wall ingrowth development were observed within the same cell.